Doesn't work properly yet in Trac 0.11. Tickets cannot be moved from column-to-column. This is because Trac 0.11.x uses jQuery 1.2.6, which forced me to rollback to jQueryUI 1.6. I am not sure yet if this version supports using Sortable across lists the way I am in the 0.12 version.

Also changed transaction handling to use 0.11.x API. Haven't actually tested this though since I can't drop tickets in different columns.

Initial i18n has JS code left out intentionally, since all translateable
strings are expected to get removed from there soon.
List templates needed substancial changes done here, including moving
translateable strings out to plugin.py to get them recognized at all.

Cherry-picked modifications needed for Trac 0.12 from changesets r7973 andr7981, that were not present in dev branch, since it was branched
from 0.11 after 0.12 and changes there went back into dev only with
changeset r8452 after i18n was branched.

Don't display a horizontal line at bottom of page if [[FootNote]] is used on a page with no footnotes (e.g. if [[FootNote]] is used in page template, so it exists on every page, but footnotes do not necessarily exist on every page)

Major code rework to straighten up the logic considerably. This should
fix another issue raised with milestone displayed at wrong day.
Thanks to Ryan J. Ollos for pre-release testing this non-trivial subject.

We perpare to develop for Trac 0.12 exclusively. While 0.11 will still be
maintained for a while, there is no need for 0.11dev anymore.
Furthermore we'll start backporting important things from trunk instead.